When a program is running in a CPU (Central Processing Unit) or other PU, local hot spots can develop on an integrated circuit chip. Present day chips are configured with islands of circuitry where different islands perform different functions in the PU operation. On a multiprocessor chip, each island may be a separate PU. In either event, each island is likely to experience different workloads and thus reach different “hot spot” temperatures. Known prior art responses comprise shutting down all processing operations of the processor until the chip is adequately cool, decreasing operational workload in a standardized manner for all software used on the PU or increasing the cooling air flow used to lower the temperature of the chip.
It would be desirable if a method could be devised whereby the PU could be allowed to continue to operate, but the hot spot islands of the PU would be substantially immediately required to run at a reduced capacity while the hot spot cools. It would be further desirable to reduce the load on the hot spot island as a function of the amount of overheating of the island in question.